Acoustic Resonance Weapons for Drone Interdiction

Acoustic waves can affect two important components of multi-rotor drones, more formally called multi-rotor unmanned aerial vehicles (UAV). The first is located in the electronic board, the so-called IMU (Inertial Measurement Unit), which can be influenced by intense sound waves at resonant frequency. The second is the motor-propeller unit of drones. Multi-rotor drones generate low-frequency acoustic emissions during flight; if external acoustic waves achieve resonance with these blade-induced vibrations, they can cause structural fatigue or mechanical failure in the motor-propeller unit. The paper addresses the following issues: first, the influence of resonant frequency sound waves on these two design elements and their performance evaluation; second, the feasibility of an integrated counter-UAV system comprising acoustic Direction of Arrival (DoA) estimation and Blade Passage Frequency (BPF) detection; and third, a new solution for a long-range directional sound effector. This proposed solution includes determining the operating frequency as the 3rd to 5th harmonics of the BPF. Furthermore, it introduces a new concept that, instead of using a standard array of sound drivers, utilizes a limited quantity of powerful drivers arranged skeletally according to a Vicsek fractal topology. This configuration generates a powerful, needle-like acoustic beam capable of delivering effective mechanical disruption multi-rotor drones at long ranges.